Commercial production of stone fruit in New Zealand is practically restricted to five species of the genus Prunus; namely, P. persica, peaches (including nectarines); P. salicina, Japanese plums; P. armeniaca, apricots; P. domestica, European plums; and P. avium, sweet cherries.

There are few districts where stone-fruit trees of one kind or another cannot be grown, but climate has an important effect on cropping. In the warmer places, partly because of lack of winter chilling, apricots, cherries, and European plums rarely crop satisfactorily. In the colder parts one limiting factor is the incidence of late spring frosts, which destroy blossoms or young fruit, while in some districts comparatively low summer temperatures do not allow the fruit to develop full flavour. Commercial growing is confined largely to a few fairly welldefined areas, which have various advantages in soil, climate, or nearness to market.

Main Districts (in Order of Size)

Central Otago, particularly around Alexandra and Roxburgh, with an area of approximately 1,600 acres, produces all five kinds of fruit, including about 80 per cent of New Zealand's total crop of apricots, 50 per cent of the cherries, and 25 per cent of the peaches. The soil is well drained, the climate is good, with a low rainfall, and low winter and high summer temperatures. In certain seasons the area is subject to late spring frosts, which would often destroy the apricot crop if fire pots were not extensively used. There is some local processing, but much of the fruit is distributed to the markets of the South Island, and apricots and cherries are sent to North Island markets as well.

Hawke's Bay, mainly around Hastings, has about 1,100 acres, three-quarters of which are in peaches, with a high proportion of canning varieties. Japanese plums are also grown extensively, but few of other kinds. Much of the orchard soil is deep and fertile and there is a reasonably good climate, with adequate rainfall, sometimes too wet during the harvesting period, with an occasional damaging late spring frost. Considerable quantities are canned locally, but much of the fruit is sent to the main North Island markets.

Auckland, within about 25 miles of the city, with an area of about 800 acres, produces mainly peaches and Japanese plums, which are practically all sold as fresh fruit. Several types of soil are used, some far from ideal, and rainfall is generally too high, but these disadvantages are outweighed by closeness to the largest market in New Zealand.

Smaller Districts

Canterbury, mainly near Christchurch City, on an area of 240 acres, grows all five kinds of stone fruit, especially apricots. There is no processing and most of the fruit is sold locally, though some apricots are shipped to the North Island. Nelson, in the Waimea Valley and near Motueka, has 220 acres, largely in peaches, much of the crop being canned locally. Poverty Bay, around Gisborne, with 75 acres, grows mostly peaches for canning. The Waikato, at Te Kauwhata and close to Hamilton City, with 75 acres, produces mainly peaches and Japanese plums for local sale. Marlborough, close to Blenheim, with 60 acres, grows peaches and cherries, the latter particularly for North Island markets. South Canterbury – North Otago, especially near Kurow, has some 60 acres in apricots, cherries, and peaches, mainly for South Island markets.

Varieties of Stone Fruit Grown (in Order of Harvesting), and Number of Trees (in Thousands), 1963

*Prunus cerasifera, but included in European plums for convenience

Production

Production is steadily increasing, but can fluctuate widely from season to season. The main influences are the incidence of late spring frosts (which can affect particularly the apricot crop in Central Otago), disease (e.g., brown rot), and droughts (which prevent the fruit sizing normally and induce premature ripening). Much of the peaches and apricots are processed (mainly canned), but most nectarines, plums, and cherries are sold as fresh fruit. In some places orchards do a considerable retail trade, but the greater part of the crop is sold through the auction markets in the main centres. There is no organised distribution system, so that returns tend to be erratic, with alternate gluts and shortages in particular markets.

Pests and Research

Stone fruit is attacked by many insect pests, physiological disorders, and fungous, bacterial, and virus diseases. The most serious of those affecting the actual trees are silver leaf, caused by the fungus Stereum purpureom, and blast of stone fruit, due to the bacterium Pseudomonas syringae. The former, in particular, takes a steady toll each year, more especially of peach trees. No satisfactory economic control has yet been developed for either of these diseases. The main disease attacking the fruit is brown rot, caused by the fungus Sclerotinia fructicola. Incidence fluctuates widely from season to season and from district to district; in some seasons, in spite of frequent spraying, much fruit of individual varieties may be lost just before harvest. Research on these and other problems is being carried out by Plant Diseases and Fruit Research Divisions of the Department of Scientific and Industrial Research, and field trials are being made by the Horticulture Division of the Department of Agriculture.

Varieties

Some of the varieties grown are old standard overseas ones brought here either direct from England or through Australia in the early days of commercial planting, from 1870 onwards. Others having since been imported at various times from Australia and, to a lesser extent, from the United States (e.g., many of the Japanese plums introduced by Luther Burbank). A few, such as Golden Queen peach and Goldmine nectarine, were raised in New Zealand.

by Alfred Thomas John Watts, B.A., Horticulture Division, Department of Agriculture, Hamilton.